Insulation cutter



July 16, 1953 A. l.. LANGSTAFF 3,097,557

INSULATION CUTTER INVENTOR. AL BE RT L. LANGSTAFF ATTORNEYS July 16, 1963 A. 1 LANGSTAFF INSULATION CUTTER 2 Sheets-Sheet 2 Filed April 6, 1960 INVENTOR. 63 ALBERT L. LANGSTAFF ATTORNEYS United States Patent O 3,097,557 INSULATEN CUTTER Albert L. Langstaif, Moran, Mich. Filed Apr. 6, 1960, Ser. No. 20,428 4 Claims. (Cl. 83-454) The present invention relates to a cutting apparatus :adapted to cut heat insulating materials such as glass wool, fiberglass and the like or similar matted materials.

Heat insulating materials such as glass wool, fiberglass and the like are normally available `to the user in bats or in roll form that require cutting 4into specific lengths as the material is being installed. In cutting the insulation material it has been found that it is necessary to have ya cutting instrument that will provide uniform and clean cuts and yet one that is simple to operate. Cutting instru ments such as shears `and knives fail to fulfill these requirements since they become dull very quickly, due to the abrasive qualities of many insulation materials, and therefore require frequent sharpening. ln addition, these instruments even in the hands of skilled workmen often Ifail to provide uniform and `clean cuts.

The present invention uses a taut wire as a cutting element and with a clamp for securely holding the insulation material While it is being cut. At the beginning of the cutting operation, the cutting wire -is disposed in a longitudinal slot in a base assembly. A pair of clamping members are movably mounted on the base assembly and are movable to a Working position to hold the material to be cut in overlying relation to the base assembly. The clamping bars are spaced a short distance apart to define an elongated aperture in alignment with the longitudinal slot in the base assembly and are held in said working position by a latch mounted on the base assembly. The cutting wire has one of its ends attached to holding means mounted on the base assembly and has its other end attached to a slide that is movably mounted on a support mounted on the base assembly. The cutting operation is performed by placing the material to be cut on a Working surface of the base assembly, moving the clamping members to the working position where they are engaged by a latch mounted on the base assembly, and then moving the slide upwardly on the support thereby drawing the cutting wire from the longitudinal slot and into shearing engagement ywith the material and then through the elongated `aperture defined by the clamping members. As `soon as the material has been completely severed, the operator is allowed to slide by gravity downwardly to a position where it disengages the latch holding the clamping members yand the clamping members are urged out of the Working position by a spring mounted on the base assembly.

One of the principal objects of this invention is to provide an insulation cutter as outlined above which is lightweight, simple to operate and is capable of cutting insulation material in a clean `and uniform manner.

Another object of this invention is to provide a cutter as outlined -above which is of simple construction and is inexpensive to manufacture.

A still further object of the present invention is to provide a cutting instrument which does not require periodic sharpening and which will function with a minimum amount of maintenance.

It is also a particular object of this invention to provide a cutting -apparatus as outlined above which will securely hold the material being cut and can be operated in such a manner that the operator of the apparatus is required to have only a minimum 4amount of direct contact with the insulation material. This is particularly important due to the face that many insulation materials are of `such `a nature that they may cause painful injury to ICC a person handling them. It is also well known that certain insulation materials will cause severe dermatitis or other allergic reactions in many individuals when they 'are brought in prolonged contact with the material.

Other objects and advantages of the invention will be apparent from the -following description, the accompanying drawings and the appended claims.

In the drawings- FIG. l is a View in side elevation, partly broken away, of the insulation cutter with the clamping members shown by solid lines in a working position and shown out of the working position by broken lines;

FIG. 2 is an enlarged cross sectional View taken on the lines 2 2 of FIG. 1;

FIG. 3 is an enlarged cross sectional view taken on the lines 3 3 of FIG. 1;

FIG. 4 is a fragmentary enlarged plan view, showing the ends of the clamping members in engagement with latching means;

FIG. 5 is a fragmentary enlarged plan View, partly in section, taken on the lines 5-5 of FIG. 1;

FIG. 6 is a fragmentary enlarged View in side elevation of the clamping member supporting means;

FIG. 7 is a partially Iassembled View of the base assembly of the cutter to show the relation of -some of the parts;

FIG. 8 is a perspective view of the insulation cutter at the beginning of the cutting operation with the clamping members out of the working position;

FIG. 9 is a perspective view showing the cutter during the cutting operation with the clamping members held in the working position, as the cutting wire is being brought into shearin g engagement with the insulation material; and

FIG. l0 is a perspective view showing the cutter upon completion of the cutting operation after the slide has disengaged the latching means holding the clamping members, as the clamping members are moving out of the working position.

Referring to the drawings, which illustrate a preferred embodiment of the invention, FIG. l shows an insulation cutter including an elongated -base assembly indicated generally Iat 10. The base assembly includes a hinge plate 11 at one end thereof and a support base plate 12 at the other end, as shown in FIG. 7. The plates 11 and 12 are interconnected in spaced relation by means of a pair of angle irons 13 and 14 which are secured to the hinge plate 11 by machine screws in a hinge block 15. The angle irons 13 and 14 are further secured by machine screws to the plate 12 at a V-block 16. The blocks 15 and 16 are, in turn, suitably bolted to their respective plates 11 and 12.

The angle irons 13 and 14 are spaced so as to define a narrow elongated slot 17 between their horizontal anges. A cutting wire 18 is arranged to extend within the space between the irons 13 and 14 within the elongated slot `-17 in the at-rest position of the cutter. A pair of wooden sills 19 and 20 are fastened at opposite ends to the plates 11 and 12 to form a ramp adjacent the irons 13 and 14. The horizontal arms of the irons 13 and 14 form a Working surface 21 yfor the cutter.

The hinge block 15 constitutes support means for movably supporting clamping means for holding material to be cut on the working surface 21. A shaft 23 having flange portions 24 and 25 is supported in grooves 26 and 27 yformed in the hinge block 15 with the portions 24 and 25 abutting the sides of the hinge block to prevent longi tudinal movement of the shaft. A plate 28 is mounted on the top of the hinge block 15 and engages the shaft 23 to journal it within the grooves 26 and 27. The clamping members Z9 and 30 are angle irons having upright and horizontal arms with inner ends welded to the shaft 23 with their upright arms abutting the inner sides of the anges 24 and 2,5. The, horizontal arms. of the clamping members abut flat :bottom sides 31 and 32 `formed on the anges. The upright arms of the clamping members deline a nar-row elongated aperture 33 which is in alignment with the slot 17 in the base assembly. The horizontal arms of the clamping members define a clamping surface indicated generally at 34.

The clamping members 29 and 30 are mounted on the shaft 23for movement into a working position, as shown in solid lines in FIG. l, where they are in overlying relation to the working sur-face 21 of the vbase assembly. The clamping surface 34 defined by the clamping members is a slight distance above the working surface 21 of the base assembly leaving a space for the material that is clamped between the surfaces. The material being cut is held between the clamping surface 34 and the Working surface 21 and is `compressed in the area adjacent the line where the cut is to be made. The material in this compressed state is severed in a clean fashion by the cutting wire.

Spring means are mounted on the base assembly for urging the clamping members out of the working position. The spring means include torsion springs 36 mounted on the ends of the shaft 23 which extend outwardly from the binge block `15. The springs each have an inner end 37 which extends outwardly from the main portion of the spring and engages pins 38 mounted in and extending tfrom the outer sides of the hinge block. Stop nuts 39 are threadedly mounted on each end of the shaft 23 and are secured against rotation on the shaft by means of the cotter keys 40 mounted through holes in the nuts and in the shaft. The torsion springs 36 have an outer end portion 41 which extends from the main portion of the spring and engages the inwardly extending lingers 42 of the nuts 39. The shaft 23 is spring -loaded so as to create a force to rotate the shaft and to thereby pivot the clamping bars out of the working position up and away from the base assembly into a position as shown in dotted lines in FIG. 1.

The plate 28 mounted on the top yof the hinge block includes a finger 43 angularly oriented upwardly in alignment with the clamping members 29 and 30. The linger 43 serves as a stop to limit the upward travel of the clamping members when they move out of the working position.

An upright support 44 is mounted on the support base plate 12 of the base assembly. A slide 45 is mounted on the support and is movable relative thereto. A cap 45 is mounted on the upper end of the support to limit the upward travel of the slide 45. The slide 45 includes an integral handle 46 and an integral cutting wireV supporting iinger 47. An elongated key l48 on the support 44 extends into a keyway 49 in the slide 45 to prevent relative rotation between the slide 45 and the support 44. The handle 46 of the slide includes a guard 51 which has a screw 52 threadedly mounted in and extending downwardly from its lower portion.

One end `of the cutting wire 18 is attached to holding means mounted on the :base plate 11 of the base assembly. rEhe holding means includes a block 53 secured to the base plate 1.1 which has a screw 54 threadedly mounted therein. The screw 54 has an eye 55`in its outer end. A tension spring 56 having a hook portion 57 is engaged in the eye 55V and the cutting wire 18 is attached t0 a book 58 at the other end of the spring. The other end of the cutting wire 18 isV attached to the pin 59 mounted in the wire supporting finger 47 of the slide 45. The cutting wire is thus held in a tensioned relation between the spring 56 and the nger 47. The tension of the cutting wire may be adjusted by rotating the screw 54 to regulate the tension of the spring. The cutting wire extends through a countersunk bore 61 in the block l15 adjacent the spring 56. A cover 63 `surrounds the spring 56 and is secured to the block by means of a screw.

Latehing means are mounted on the support base plate 12` of the base assembly adjacent the support for releasablybolding the clamping members 29 and 30 in a working position. The latching means includes a substantially U-shaped latch plate 64 surrounding the, upright support 44 which is pivotally mountedi on pins `65 extending from the sides of the blocks 65 mounted on the support base plate. The latch plate 64 includes latch lingers 66 on the inner ends of its legs which are adapted to engage the end portions of the clamping members 29 and 30 to hold them in `the working position as is clearly shown in FIG. 4.

A spring 68 is mounted on a dimple 69 formed on the support base plate beneath the latch plate 64 and urges the plate 64 .to move the lingers downwardly into engagement with the ends of the clamping members. When the slide 45 moves downwardly on the support 44, it engages Ithe latch member, and the screw 52 depresses the plate 64 and acts against the force of the spring 63 to pivot the latch lingers 66 upwardly and out of engagement with the ends of the clamping members. The slide 45 after depressing the latch `64 by Ithe screw 52, is raised slightly by the spring 68 to its normal operating position and is now ready lfor the next cut. After the latch lingers have been disengaged, the clamping members are free to move upwardly away from the base assembly due to the force exerted by the torsion springs 36 mounted on the ends of the sha-ft 23.

Small ySlot 7d are formed at the inner ends of each clamping member adjacent the point where the latch tingers 66 engage `the clamping members. The outermost ends of the clamp members 29, 3@ carry a pair of blocks '71, provided as a. convenient handle to lower into clamping position. Guide means are provided to hold the clamping members in parallel relationship to define a uniform aperture 33 as they are brought into the Working position and to hold this relation during the cutting stroke. The guide means includes the V-block 16 which has a substantially V-shaped slot 72 formed therein. Also, guides 73 are formed on the members 29 and 30. As the clamping members 29 and 30 are brought into overlying relation -to the base assembly, the guides 73 engage the sides of the slot 72 to hold the ends of the clamping bars in parallel relationship and prevent spreading during the cutting stroke.

The sequence of operation of the invention is clearly shown in FIGS. 8, 9 and l0. The bat 75 of insulation material is unrolled and is placed on the working surface of the baise assembly with the line of the desired cut in alignment with the slot 17 in the base assembly. The slide l45 is moved downwardly to a position where it engages the latch plate 64 to overcome the force exerted by the spring 68 and the latch lingers 66 `are moved upwardly. The clamping members 29 and 30 are then manually brought downwardly compressing the material. The force being exerted on the slide is then released and the spring 68 pivots the latch plate into a position Where the latch fingers `66 engage the ends of `the clamping members. The slide is then pulled upwardly, as shown in FIG. 9, drawing Ithe cutting wire 18 from the slot 17 in the base assembly into shearing engagement with the material and through the aperture 33 between `the clamping members. The `slide is pulled 'upwardly until the wire 18 has completely severed the material and is then allowed to drop downwardly where it engages the latch plate 64 to disengage the latch lingers 66 `from the ends of the clamping members. The force exerted by the torsion springs 36 then swings the clamping bars away from the base assembly as shown in FIG. l0. The pieces of insulation material may then be removed 'and the cutting apparatus is in position to receive another piece of material to be cut.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing `from the scope of t-he invention which is defined in Athe appended claims.

What is claimed is:

1. Apparatus for cutting insulation material comprising an elongated base assembly having a longitudinal slot therein adapted to receive a cutting wire, a pair of clamping lmembers movably mounted on said base assembly for movement to a working position to hold material to be cut in overlying relation to said base assembly, said clamping members defining an elongated aperture in alignment with said slot, holding means mounted `on said base assembly, a cutting Iwire disposed in said slot having one end attached to said holding means, an upright support mounted on said base assembly, a slide mounted on said upright support and movable between upper and lower limit positions, said wire connec-ted to said slide in tensioned relation, a latch plate pivotally mounted on said base assembly, said latch plate having latch lingers adapted to engage said clamping members for holding said clamping members in `said working position, means on said slide engageable with said latch plate for `disengaging said latch lingers from said clamping members with said slide in said lower limit position, said slide being movable to withdraw said cutting wire Afrom said longitudinal slot in said base assembly and into cutting engagement with said material held by said clamping members land through said elongated aperture.

2. A cutter for severing insulating material, comprising an elongated base adapted to be received on a flat surface and :defining a wire storing slot therein, an upright support mounted on one end of said base, a slide handle mounted for reciprocal movement on said upright support between upper and lower limit positions, an insulator material clamp pivotally mounted on said base at a point remote from said upright and movable into a clamping position generally parallel to but yspaced from said base, means in said clamp defining a slot in alignment with the slot in saidv base, a cutting wire having one end connected to said base within said base slot and another end connected to said handle in tensioned relation for movement in a cutting stroke upwardly with said handle through said base and clamp slots with an upward pull of said handle, said handle being gravitationally returnable to said lower position by release from said upper position to return said wire into said wire storing slot of said base, a latch on said base releasably securing said clamp in said lowered clamping position, and means on said handle engageable with said latch in said lowered position for releasing said` latch upon the gravitational return of said handle.

3. The insulation cutter of claim 2` including adjusting means in said base having a connection to said one end of said wire for changing the tension in said wire.

4. Apparatus for cutting insulation material, comprising an elongated base assembly having a working surface, clamping means for holding material to be cut on said working surface, means mounted on said base assembly pivotally supporting said clamping means for movement between a raised position clear of said base assembly to a working position adjacent said working surface to hold the material to be cut on said surface, spring means mounted on said base assembly having a connection to said clamping means and arranged to urge said clamping means from said working position to said raised position, a cutting wire having one end attached to said base assembly adjacent the pivotal support of said clamping means, an upright support mounted on said base assembly remote from said pivotal support, a slide mounted on said upright support and movable thereon between lowered and raised positions, means connecting said wire to said slide in tensioned relation for movement therewith into shearing engagement with said material held on said base by said clamping means, latch means yon said base adjacent said upright support for releasably securing said clamping means in said working position, and means on said slide engageable with said latch means in said lowered position for releasing said latch means providing for the movement of said clamping means by said spring means from said working position to said raised position.

References Cited in the lile of this patent UNITED STATES PATENTS 2,609,047 Wilkoff Sept. 2, 1952 2,790,498 Carscallen Apr. 30, 1957 FOREIGN PATENTS 612,747 France Aug. 7, 1926 630,451 Great Britain Oct. 13, 1949 147,289 Australia July 9, 1952 

4. APPARATUS FOR CUTTING INSULATION MATERIAL, COMPRISING AN ELONGATED BASE ASSEMBLY HAVING A WORKING SURFACE, CLAMPING MEANS FOR HOLDING MATERIAL TO BE CUT ON SAID WORKING SURFACE, MEANS MOUNTED ON SAID BASE ASSEMBLY PIVOTALLY SUPPORTING SAID CLAMPING MEANS FOR MOVEMENT BETWEEN A RAISED POSITION CLEAR OF SAID BASE ASSEMBLY TO A WORKING POSITION ADJACENT SAID WORKING SURFACE TO HOLD THE MATERIAL TO BE CUT ON SAID SURFACE, SPRING MEANS MOUNTED ON SAID BASE ASSEMBLY HAVING A CONNECTION TO SAID CLAMPING MEANS AND ARRANGED TO URGE SAID CLAMPING MEANS FROM SAID WORKING POSITION TO SAID RAISED POSITION, A CUTTING WIRE HAVING ONE END ATTACHED TO SAID BASE ASSEMBLY ADJACENT THE PIVOTAL SUPPORT OF SAID CLAMPING MEANS, AN UPRIGHT SUPPORT MOUNTED ON SAID BASE ASSEMBLY REMOTE FROM SAID PIVOTAL SUPPORT, A SLIDE MOUNTED ON SAID UPRIGHT SUPPORT AND MOVABLE THEREON BETWEEN LOWERED AND RAISED POSITIONS, MEANS CONNECTING SAID WIRE TO SAID SLIDE IN TENSIONED RELATION FOR MOVEMENT THEREWITH INTO SHEARING ENGAGEMENT WITH SAID MATERIAL HELD ON SAID BASE BY SAID CLAMPING MEANS, LATCH MEANS ON SAID BASE ADJACENT SAID UPRIGHT SUPPORT FOR RELEASABLY SECURING SAID CLAMPING MEANS IN SAID WORKING POSITION, AND MEANS ON SAID SLIDE ENGAGEABLE WITH SAID LATCH MEANS IN SAID LOWERED POSITION FOR RELEASING SAID LATCH MEANS PROVIDING FOR THE MOVEMENT OF SAID CLAMPING MEANS BY SAID SPRING MEANS FROM SAID WORKING POSITION TO SAID RAISED POSITION. 